The present disclosure relates to a lattice point group generating method for generating a group of pre-color conversion lattice points to be contained in a color conversion table for conversion of colors in a color space having three channels to colors in another color space, a storage medium that stores therein a lattice point group generation program for generating a group of pre-color conversion lattice points to be contained in a color conversion table for conversion of colors in a color space having three channels to colors in another color space, and a lattice point group generating device for generating a group of pre-color conversion lattice points to be contained in a color conversion table for conversion of colors in a color space having three channels to colors in another color space.
A known color conversion table that is used for conversion of colors in a color space having three channels to colors in another color space is a color conversion table that is used for conversion of colors in an RGB color space to colors in a CMYK color space. When receiving RGB format image data, an image forming apparatus converts the RGB format image data to CMYK format image data using the color conversion table. The image forming apparatus then performs printing based on the CMYK format image data.
FIG. 22 is a diagram illustrating a typical color conversion table. As illustrated in FIG. 22, pre-color conversion lattice points are in a cubic lattice arrangement in the typical color conversion table. In a color conversion table in which pre-color conversion lattice points are in a cubic lattice arrangement, the number of lattice points per edge of the cubic lattice depends on the capacity of memory available to store lattice point information. A larger capacity of memory allows more lattice points to be stored per edge of the cubic lattice. However, the number of lattice points per edge of the cubic lattice is usually determined in view of desired accuracy of the quality of images to be output and component costs for the image forming apparatus. The number of lattice points necessary for a color conversion table in which pre-color conversion lattice points are in a cubic lattice arrangement is “the cube of N”, wherein the number of lattice points per edge of the cubic lattice is N. Accordingly, the number of necessary lattice points increases with increase in the number N of lattice points per edge of the cubic lattice in proportion to the cube of N.